How to install stock firmware on Asus Zenfone 3

Asus Zenfone 3 smartphone was launched on May 2016 with two-sided Gorilla glass. It runs on Android 6.0 and is powered by 4GB RAM, 3000mAh non-removable battery. Now a days many people are bricks there mobile while rooting and install custom ROM’s(flash). They are want to revert back the changes and install official stock firmwares. Here the tutorial how to install stock firmware on Asus Zenfone 3. If you are using stock firmware then connect your mobile to WiFi network then Goto → Settings → About → System Update check the update and proceed to download after download it will install automatically. If your are not using stock firmware then follow any one of the below method to install stock firmware back to your device.